Design and Implementation of a LIDAR

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Design and Implementation of a LIDAR
Evaluation of MISI for Addition of LIDAR System
and Proposed Design of LIDAR
Senior Symposium May 11, 2001 Cindy
Scigaj Advisor Dr. Anthony Vodacek Digital
Imaging and Remote Sensing Laboratory Center for
Imaging Science Rochester Institute of Technology
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What is LIDAR?

• Pulsed laser, light collection device, and a
  sensor
• Valuable tool for collecting information in the
  littoral zone

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Why LIDAR?

• Study algae growth
• Determining water depths
• Identifying objects in shallow water

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LIDAR Techniques - Fluorescence

• Pulsed light sent from LIDAR
• Light is absorbed by target
• Target fluoresces
• Fluoresced light is of lower frequency than from
  the laser
• Chlorophyll
• Green excitation - Red emission
• Colored Dissolved Organic Material
• Blue excitation - Green emission
• Ultraviolet excitation - Blue emission

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LIDAR Techniques - Elastic Scattering

• Pulsed light sent from LIDAR
• Light reflected off of target
• Return pulse is of same frequency and the time of
  flight of the light pulse is determined
• Water Depth
• surface return
• bottom return
• Green excitation - Green reflected

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LIDAR Sensor

• Sensor - Hamamatsu PMT
• 16 Different interference filters permanently
  affixed
• Eliminates the need for a separate spectrometer

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Validation of PMT

• Radiant responsivity of PMT is such that it can
  detect light at all of the wavelengths in table

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LIDAR - Light Collection Device

• Airborne Modular Imaging Spectrometer Instrument
  (MISI)
• Collects data in many spectral bands at high
  resolution
• Used for thermal calibration of Landsat 7 (in
  cooperation with ground team)

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Validation of MISI

• MISI Optical specifications put into Optical
  Software for Layout and Optimization program
  (OSLO)

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Validation of MISI

• After modeling the Cassegrain correct focal
  length of 20in and working f-number of
  3.3333 were achieved which matches the Feng
  thesis specifications

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Proposed LIDAR Design
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OSLO Analysis

• Modulation Transfer Function for Cassegrain using
  0.6943µm wavelength source

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Acknowledgements

• Dr. Anthony Vodacek
• Dr. Robert Kremens
• Bryce Nordgren

Feng, Xiaofan, "Design and Performance of a
Modular Imaging Spectrometer Instrument",
Rochester Institute of Technology Ph.D.
Dissertation, (1995).